i Elementary, Economic Experiments in Physics by Reginald F Melton INTEHWWTFONAL CLEARINGHOUSE SCIENCE TEACHING CENTER UNIVERSITY OF MARYLAND i. administrator's guide Administrator's Guide to ELEMENTARY, ECONOMIC EXPERIMENTS IN PHYSICS by REGINALD F 9 MELTON !'3 ©Reginald F. Melton, 1972 INTRODUCTION When working as a Science Education Adviser in the Philippines during the sixties Mr. R.F. Melton developed a series of elementary experiments in secondary school physics using simple apparatus. Details for the construction of the apparatus and information about the design of a suitable laboratory, workshop and storerooms were described. Although the development of the equipment was the primary objective, Mr* Melton considered that it was necessary to give an example of a course in physics for which the apparatus would be suitable. He therefore wrote a Student Guide and a Teacher's Guide to such a course in addition to a Guide to the Apparatus and an Administrator's Guide, It seemed to us in the Centre for Educational Development Overseas that science advisers and curriculum teams working in developing countries might find these guides of considerable interest and value, so the Centre arranged for a limited number of copies to be made available. It may also be of interest to note that a study called Inexpe nsive Science Teaching Equipment Wo rldwide XTS^2y7Ts~l)eing^ jmETTslTeS^eparately and"~wTTT complement these volumes published by CEDO. This study was conducted by Dr. J. David Lockard and Mr, R. ,F. Melton during 1971 at the University of Maryland Science Teaching Center, U.S.A. Produced by CEDO, Tavistock House South, Tavistock Square, London WC1H 9LL. Limited circulation June, 19 72 r i Author's Foreword "To all my friends overseas" The author spent ten years in developing countries, working for the British Government in Turkey and the Philippines and for the Ford Foundation in Pakistan. During that time he became acutely aware of the problems facing developing countries in the field of science education , and it is his hope that 'Triple E Physics' will contribute in some small way to the major tasks that lie ahead. 'Triple E Physics' emerged from a wealth of experiences shared with educators, scientists and friends overseas, and it would seem fitting that this book should be dedicated to those many friends who made the author's work in developing countries such a rewarding experience. The author was until recently the Associate Director of a project for the development of "Improvised Science Teaching Equipment Worldwide" at the Science Teaching Center of the University of Maryland (USA). ! 1 Table of Contents Page 8 1. WHY 'TRIPLE E PHYSICS'? 1 2 9 WHAT IS 'TRIPLE E PHYSICS'? 2 3, APPARATUS DESIGNS 4 3*1 Modification of Existing Item Types 4 3 9 2 New Item Types 8 3 9 3 Kits 4 9 APPARATUS REQUIREMENTS AND COSTS 9 4 9 1 Apparatus Requirements 11 4 9 2 .Additional Requirements 14 5 8 IMPLEMENTATION OF 'TRIPLE E PHYSICS' 16 6 8 APPARATUS PRODUCTION 18 6*1 Student and Teacher Production 18 6.2 Technical School Production 19 6 9 3 Factory Production 19 6 9 4 Cottage Industry Production 19 7 9 WORKSHOP FACILITIES 20 7*1 Hand too Is 20 7,2 Machine Tools 22 7 9 3 Raw Materials 24 7„4 Adhesives 26 7 9 5 A Workshop Plan 27 8„ LABORATORY FACILITIES 28 8 9 1 The Economy Laboratory 8 9 2 The Normal Laboratory 28 42 !• _ W !' 1Y 'Ji'^k^ A ™§ics^ When the Physical Science Study Committee (PSSC) began its work in the United States in late 1956 it started a movement which is now revolutionizing the teaching of science* Breaking away from traditional ideas the PSSC will be remembered in the same spirit as the first four minute mile, as a foretaste of things to come. Since then science projects have mushroomed , leaving us with little doubt that we are at the beginning (not the end) of a period of revolution in science teaching. Teachers in developing countries are daily growing more and more aware of the new ideals and methods being generated , but far too often are unable to benefit from the dynamic winds of change sweeping through the field of education. The reasons for this are fairly clear. Adoption of new programs in Developing Countries makes little sense if such programs are either unsuited to a country's academic needs or are beyond what a country can reasonably afford. Teachers are realistic in such matters and recognize the need to modify existing programs before adoption^ but it is at this stage that problems arise. What parts of a program are suitable for adoption? What apparatus should be purchased , given limited financial resources? What does one do if apparatus requires sophisticated laboratory facilities? How far can a program be modified without destroying its essential character? It is usually at such a stage that frustration sets in. What can teachers do alone without the essential guidance and support needed to modify materials , and without the necessary resources to develop facilities? It was very much with such questions in mind that 'Triple E Physics' was developed. _ 2 - 2 a WHAT IS 'TRIPLE E PHYSICS 1 ? 'Triple E Physics' is a package of materials developed to help educators introduce a scientific , inquiring approach into the teaching of physics in Developing Countries , Low cost apparatus , designed for production in local workshops and for use under simple laboratory conditions , is fundamental to the whole program* Equally important , however , is the integration of materials ranging from guidance for students , teachers and technicians to the provision of resource materials for administrators. The development of laboratories , workshop facilities f trial programs and in-service training are all considered equally important parts of the development machinery . More specifically 'Triple E Physics' is a package consisting of a Student Guide , Teacher's "Guide , Apparatus Guide and Administrator's Guide . The Student Guide is based on the premise that high school students in Developing Countries , like students everywhere , need to learn to understand what scientific knowledge really means and how it is built up from developing theories and experiments . They must learn to understand the uncertainties of science , and yet to appreciate its paramount importance to society • Such understanding can be developed through an inquiring approach „ placing the pupil in the position of the researcher and the teacher in the position of consultants This is not the only way of approaching the problem,, but it is a technique which has already shown considerable promise . Above all it is an approach which has been found to provide essential motivation to the majority of students , who so often in the past have been bored and disillusioned by traditional , pedagogic methods of teaching , but have been excited and awakened to the allure of science by an attitude of discovery • The Student Guide therefore presents a series of experiments which are fundamental in nature „ and as such are ideal for Introducing new concepts • Educators may select individual experiments to fit into their existing curriculum,, or f since the experiments have been developed as a logical sequence , may choose to offer the experiments as a whole , as an introductory course in physics f which is complete in itself . The Teacher's guide is based on the knowledge that very few teachers are willing to adopt new philosophies without considerable assistance. - 3 - At least the traditional t pedagogic method of teaching gives a teacher confidence , even if it offers very little else, so it is important to insure that a teacher receives sufficient guidance to enable him to proceed in new ways with confidence . For this reason the Teacher 1 s Guide contains detailed results of actual experiments along with relevant comments and suggestions,, The Apparatus Guide describes how equipment may be made in the simplest of workshops , and as such is fundamental to the whole program* The apparatus it describes has been developed specifically for Developing Countries in the realization that they have very limited economies , and that by necessity their schools have not only limited laboratory facilities f but also' stringent financial resources • Apparatus has therefore been designed for economy 9 for ease of operation under limited laboratory conditions , and for ease of production under local conditions • Apparatus has been designed specifically with students and teachers in mind f and can be made with the simplest of handtools* This has the advantage that cottage industries will have no difficulty in adapting the designs to their own requirements «, whereas the reverse situation would be much more difficult. It is in fact envisaged that cottage industries will be the major producers of equipment for 'Triple E Physics 1 , and with this in mind a few blue-prints have been added to describe the more complex items 9 However f sophisticated techniques and machinery are not required f even for the most complex items , and good local workshops should have little difficulty in handling the work, • __ The Administrator's Guide not only includes details of laboratory plans , workshop facilities and methods of production, but also a breakdown on the type of overall planning that is so essential to the implementation of any new program. Administrators must be prepared to determine for themselves what experiments might realistically be included in their curricula „ what in-service training will be required, what apparatus production will be necessary and what laboratory development will be essentials The Administrator's Guide has been written specifically to help answer such questions,, and as such is a crucial component of 'Triple E Physics' . - 4 - l?„.__^?AEATy§_9?SIGNS The Apparatus Guide contains three types of designs? modifications of existing item types , completely new items ? and items which may be grouped into kits/ All these designs take into account not only the raw materials and technical skills that are available in Developing Countries , but also their limited economies. The following examples should illustrate these points . 3.1 Modification of Existing Item Types In designing a force and motion cart it is recognized that ball bearing wheels are often unavailable in Developing Countries , or if available may be .extremely expensive . The design offered therefore makes use of simple pivot-type wheels which can readily be produced under local conditions . Frictional effects with the cart are reduced by using an inclined slope to compensate for friction* •' .J _ 5 - Similarly small electrical motors are often unavailable , or, if available , are expensive . The design of the ripple tank vibrator therefore describes a mechanical type of vibrator rather than an electrically driven one* This simplified vibrator still permits the realization of a whole range of wave motion experiments with the ripple tank* - 6 - Production of optical prisms and lenses from glass requires specialized technical skills , but the Apparatus Guide describes how these may be made from plastics (acrylic) with no more than a hacksaw , some sandpaper and a little metal polish,, t j U - 7 - High quality steels and alnico alloys are often extremely difficult to obtain in Developing Countries , and the production of high quality magnets becomes a major problem,, Electromagnets, however ? may readily replace normal magnets p and designs making use of these in such items as moving coil galvanometers and magnetic field apparatus are included in the Apparatus Guide . 1 li 1 ) |H J s \ ^d f^^^ 0. - 8 - 3 a 2 New Item Types Although some economy may be made by modifying existing item types 9 much greater economy results if new apparatus is designed to illustrate basic concepts • For example 9 the concept that bodies fall with the same gravitational acceleration^ if unaffected by friction from the air 9 may be demonstrated at considerable expense with the help of an evacuated tube g a feather and a piece of metal (the usual "guinea and feather experiment"),, However „ it may be presented equally well with a stone and a sheet of paper , The Student Guide lists materials such as the paper and stone 8 along with other items of apparatus 9 and indicates how these may be used to develop particular concepts * Thus relative motion is studied with pieces of paper „ while forces are studied with strips of metal 9 sponge rubber 9 modelling clay ? wire and syringes 9 3 9 3 Kits The Student Guide groups activities together by concept % introducing each with a list of apparatus (the kit) required to study the concept* This means that although a single item (e 9 g 9| ripple tank) may be relatively expensive , the cost per experiment is relatively^ low since the accessories make it possible to perform a whole series of experiments,, n - 9 - 4, APPARATUS REQUIREMENTS AND COSTS The following lists indicate the total equipment that would be required by a class of 32 students undertaking all the experiments presented in 'Triple E Physics ', It is strongly recommended that laboratory classes should not exceed 32 students per teacher, and that students should normally work in pairs , although occasionally (e„g, 9 for ripple tank work) groups of 4 are permissible. It follows that equipment is required in multiples of 16 9 and occasionally 8, for class experimentation. If only one item of equipment is listed in a particular kit this indicates that the item is to be used on a rotational basis by students 9 or as a demonstration item by the teacher , Clearly , teachers and administrators will wish to adjust these lists according to the number of experiments to be adopted in their curricula and according to the class size envisaged. It is suggested that equipment producers should pack the apparatus in class kits, that is 16 (or 8 9 etc) pieces of the same equipment per box as indicated below. If the kits are packed in shallow cardboard boxes from which the top and half the front may readily be removed the boxes will serve as storage trays, thus permitting a teacher to select an appropriate set of apparatus with the minimum of inconveniences The teacher will probably find it convenient to store the apparatus in the same order as that given in the following lists. It is of interest to record that 3 sets of equipment for 'Triple E Physics' were produced and tested in the Philippines between 1966 and 1969, The cost of the raw materials required to produce the apparatus was estimated on this basis , and it was determined that equipment listed below could be produced at a cost_ of $207 dollars (1969 estimate). This does not include the cost of labor which - 10 - could more than double the final cost Involved » Clearly costs vary from country to country 9 but 9 taking into consideration the 139 activities which may be undertaken with the 'Triple E Physics 1 materials 9 it would appear that there is some justification for suggesting that the experiments are economic in nature 8 * n * The 139 activities includes MEASUREMENT 19 activities FORCES AND MOTION 47 WAVE MOTION 17 OPTICS 33 ELECTRICITY 23 Taking into account the raw material cost only s the total 'Triple E Physics' materials costs $207 dollars per class of 32 students per 139 activities or $0 9 07 dollars per student per activity » - 11 - 4.1 Apparatus Requirements Item No. Apparatus 1,10/01 Triangulation Device 1. 10/02 Displacement Block 1. 20/01 Balance l 9 20/02 Box of Weights 1.20/03 Microbalance 1.30/01 Ticker Tape Timer or [1.30/02 Alternative Ticker Tape Timer (Blue-Print)] 1.40/01 Relative Motion Frame 2.10/01 Wire Extender 2.10/02 Wire Spring, Copper Wire Spring t Steel 2.10/03 Rebound Apparatus 2.10/04 Spring Balance^ 1 Newton Spring Balance 9 10 Newtons 2.10/05 Puck 2.10/06 Friction Tube with Stand 2.20/01 Simple Cart or [2.20/02 Cart (Blue-Print)] 2.20/03 Inclined Plane 2.20/04 C Clamp 2.40/01 Inertial Balance 2.50/01 Elastic Collision Runway 2.60/01 Centripetal Force Apparatus 2.70/01 Dynamo /Motor or [2.70/02 Dynamo /Motor (Blue-Print)] 2.70/03 Simple Machine 3.10/01 Ripple Tank 3.10/02 Ripple Tank Accessories 3.10/03 Stroboscope Quantity 16 16 16 16 16 16 16 1 16 16 1 16 16 1 1 16 16 16 16 8 1 16 8 8 8 - 12 - Item Nq^ j^R^^tus SHfS^jUr^ 4.10/01 Light Source with Base 16 (8 sources already available with Ripple Tanks) 4 . 10/02 Slit/Aperture Combination 16 4* 10/03 Mirrors, Plane 16 Mirrors % Curved 16 4*10/04 Optical Board with Fins 16 4 . 10/05 Optical Prisms f Rectangular 16 Optical Prisms % Triangular 16 Optical Prisms „ Semi-circular 16 4 . 10/06 Refraction Model Apparatus 16 4.10/07 Screen with Holder 16 4 . 10/08 Filter (Red) 16 4 8 20/01 Single and Double Diffraction Slits 16 or [4. 20/02 Adjustable Diffraction Slit (Blue-Print)] 4 . 20/03 Simple Diffraction Holes 16 4*30/01 Multiple Slit 16 4.30/02 Lens Holder 16 4*30/03 Interference Strips f Copper 2 Interference Strips , Steel 2 5.10/01 Dry Cell Holder with Cells 32 5.10/02 Bulb Holder with Bulb 64 5,10/03 Switch 32 5 . 10/04 Multipurpose Coil with Cores 32 5 , 10/05 Compass 32 5.10/06 Magnetizing Coil 1 Cylindrical Magnets (5 cms long, 0*8 cms diameter) ,32 5 . 10/07 Tangent Galvanometer 16 5 . 10/08 Magnetic Field Apparatus 16 or [5,10/09 Magnetic Field Apparatus with Multipurpose Coils] (Multipurpose Coils already available) 5.10/10 Moving Coil Galvanometer 16 or [5 „ 10/11 Moving Coil Galvanometer with Multipurpose Coils] (Multipurpose Coils already available) or [5.10/12 Moving Coil Galvanometer (Blue-Print)] (Multipurpose Coils already available) - 13 - Item No. Apparatus Quantity 5,20/01 Neon Bulb Holder with Bulb 16 5.20/02 Electricity Tester 16 5.20/03 Resistor Holder with Resistor 16 5.20/04 Chemical Cell 16 - 14 - l l °.?. ... Add 1 t ional Requirements Apparatus Ball Bearings t diameter 0.8 cms Ball Bearings 9 diameter 1 8 2 cms Ball Bearings g diameter 2.4 cms Balls , Brass „ Centrally Drilled , diameter 1.2 cms Balls , Brassg Centrally Drilled f diameter 2*4 cms Barriers , Wooden (8x 3x0,8 cms) Blocks $ Wooden (10 x 6 x 4 cms) Bottle Tops Bulbs (2*5 volts, 0.3 amps) Bulbs (6*2 volts , 0.3 amps) Cardboard Strips (10 x 2 cms) Chalk Container , Plastic (approximately 10 cms deep 9 10 cms diameter) Cork (1 cm diameter , 0.5 cms deep) Cubes , Sponge Rubber (5x3x2 cms) Cubes , Wooden (4x4x4 cms) Hacksaw Hammer Lead Strips (10 x 5 x 0.1 cms) Lenses , Hand (focal length 10 to 20 cms) Metal Strips „ Alloy (20 x 1.5 x 0.05 cms) Metal S trips f Lead (20 x 1.5 x 0.05 cms) Metal Strips, Steel (20 x 1.5 x 0.05 cms) Modelling Clay Nails (1 cm long,, approximately) Nails (10 cms long § 0.7 cms diameter) Needles (3 cms long) Olive Oil Paper , Carbon (22 x 28 cms approximately) Paper , Plain White (22 x 28 cms approximately) Paper Clips (100) Plastic Strips (10 x 2.5 cms) Protractors Rings , Metal (diameter 0.5 cms) 16 16 16 16 16 16 32 8 64 16 16 1 box 2 8 32 32 4 4 8 16 16 16 16 - 1 kgm 1 kgm 1 kgm 50 0.5 liters 50 sheets 2 reams 4 boxes 32 16 16 - 15 - Apparatus Rubber Bands (100) Rubber Bands, Chain of (40 to 50 cms long) Rulers , Meter Salt Sandpaper (20 x 20 cm approximately , varied grades) Screws, Cup Set Squares (approximately 10 x 17 x 20 cms, or bigger) Soap Solution (dish washing liquid) Springy Door (35 cms long, 1 cm diameter approximately) String, strong and thin (50 meters) Syringe 9 Plastic (without needle, minimum diameter 1 9 5 cms, minimum volume 10 ccs) Thumb Tacks (100) Ticker Tape (25 meters) Vinegar Wire, Copper (Plastic or Cotton Covered, #24) Wire, Magnet (#24) Wire, Magnet (#26) Wire, Steel (#26) Wire, Steel (#30) Quant tity 8 boxes 40 16 9 5 kgm 32 sheets 200 32 2 bottles 1 2 balls 16 2 boxes 4 rolls 4 liters 2 kgm 1 kgm a 5 kgm 9 5 kgm 0,5 kgm _ 16 - 5 a IMPLEMENTATION OF ? TRIPLE E PHYSICS 1 It is possible for a well motivated school to adapt the whole 'Triple E Physics' program without outside help* It would of course be responsible for its own apparatus production^ laboratory development and teacher orientation , and there is no doubt that this would be a major task. In general it is hoped that science education centers $ supervisors and administrators will provide teachers with the help that is needed on a regional basis • Such individuals and centers can determine which experiments might best be integrated into the curriculum,, They can designate local workshops for apparatus production and arrange some system of technical guidance and quality control* They can survey existing laboratory facilities and recommend essential developments 8 In addition they can arrange for teachers to receive appropriate in-service training in the materials 9 insuring a well orientated teacher returns to the class room. It is recommended that materials should be introduced in the first instance on a trial basis , for however well the materials might have worked elsewhere it is important to determine whether students have problems with the materials f and whether teachers are able to handle them adequately • It is important to recognize production problems at an early stage t and problems such as these are best detected by a limited trial of the materials • The following chart summarizes the processes which might be introduced to insure a successful implementation of the materials . - 17 - Preview In-service Training Production and testing of one complete set of 'Triple E Physics 1 materials by small groups of educators and technicians,, Decision as to which materials should be adopted in existing curriculum* Exposure courses for limited number of teachers 9 administrators and technicians to be involved in future trials and subsequent in-service training* School Trials Feedback to be obtained on all aspects of materials 9 modifications being made as required* In-service Training i In-service training for teachers f administrators and technicians to be involved in large scale adoption of materials Targe Scale Adoption Large scale adoption of materials as desired Tre-service" Training Inclusion of adopted materials in regular pre-service training programs 9 - 18 - 6 @ APPARATUS PRODUCTION In looking around for suitable apparatus producers it is almost certain that administrators will give some thought to the use of students and teachers , technical institutions , factories and cottage industries , and a brief comment on each might be helpful • 60 1 _ S tudenf, &'aA.J?S^^---~—~^~- Students and teachers are encouraged to make items for themselves , for apparatus development can bring both students and teachers into close contact with the realities of science , relating science and technology in the simplest of ways* However, this does not mean that students and teachers should attempt to produce all their own apparatus requirements . It is recognized that teachers have specific curricula to follow, and that "class hours" available for such work are very limited . It would therefore appear to be more realistic to look to other sources for mass production of apparatus . 19 - 6 „ 2 Te chnlca^S^o^^i^^^tlon^^ Another alternative often considered is the use of students in technical schools as production units . Any such plan should again take into account the fact that technical institutions are primarily training centers and not mass-production units • However „ valuable training in scientific instrumentation can be gained by involving students in some form of apparatus production. Many countries look to new government factories to solve their equipment problems , and here^ too ? one might add a word of caution* Such plans require considerable input in the way of machines and training of personnel , while care must be taken to avoid the typical red tape and bureaucracy that so often accompany' government-run organizations . The fourth alternative , and in many ways the most desirable 9 is to look to the so-called cottage industries which exist in developing countries. In these small industries, there are many workshops with hand tools and simple lathes and drill presses , and there are enough semiskilled workers to operate them* So long as apparatus is designed with these conditions clearly in mind f it can be produced without building new factories or undertaking major training programs. At the same time useful work can be offered to a number of relatively underemployed people 8 _ 20 - 7. WORKSHOP FACILITIES Any workshop wishing to produce reasonable quantities of equipment will wish to procure the majority of the following handtools. Chisels (Wood) 3, 6, 9, 12, 15, 18, 21, 24 mms (i.e., 1/8", 1/4", 3/8", 1/2", 5/8", 3/4", 7/8", 1") 8 Cutters Bench Shears, 3 mm (1/8") capacity 1 Glass Cutter 1 Knife 1 Scissors, 200 mm (8") 1 Snips (Tinmans), Straight, 200 mms (8") 1 Snips (Tinmans), Curved, 200 mms (8") 1 Taps and Dies, 3 to 12 mms (1/8" to 1/2") set 1 Drills and Borers Cork Borer Set 1 Countersink, 90° 1 Metal Drill Holder (Electrically Driven), Capacity 6 mm (1/4") 1 Metal Drills, 0.5, 1, 2, 3, 4, 5, 6, 7 mms (i.e., 1/32", 1/16", 3/32", 1/8", 5/32", 3/16", 7/32", 1/4") set 1 Wood Brace with Ratchet, 250 mms (10") 1 Wood Augur, Bits 6, 12, 18, 24 mms (I.e., 1/4", 1/2", 3/4", 1') 4 Files (Double Cut) Flat, 100 mm, 200 mm (4", 8") 2 Round, 100 mm, 200 mm (4", 8") 2 Triangular, 100 mm (4") 1 Hammers Ball Pein, 125, 250, 500 grams (1/4, 1/2, 1 lbs) * 3 Claw 250 grams (1/2 lb) 1 Measuring Aids Caliper (Inside) 1 Caliper (Outside) 1 Caliper (Vernier) may replace above two items 1 Dividers, 150 mms (6"), Toolmakers 1 Meter, Electrical (Multipurpose - volts, ohms, amps, etc.) 1 Meter Stick 1 Scriber 1 Square, Carpenter's, 300 mm (12") blade 1 Square, Try, 150 mm (6") blade 1 - 21 - Planes Spoke Shave, 18 mm (3/4") 1 Wood Smoothing Plane 1 Pliers Combination* 150 mm (6") 1 Long Nose, 150 mm (6") 1 Side Cutting, 150 mm (6") 1 Saws (Metal) 300 mm (12") blades 1 (Wood) Cross Cut* 600 mm (24") 1 Hand Rip, 600 mm (24") 1 Tenon, 200, 300 mm (8", 12") 2 Screw Drivers 100 mm (4"h with 2 and 3 mm tips 2 150 mm (6"), with 5 mm tip 1 200 mm (8"), with 7 mm tip 1 Vices Engineers Bench Vice, 75 mm (3") 2 Wood Work Bench Vice, 150 mm (6") 2 Wrenches (Adjustable) 100, 150, 200 mm (4", 6", 8") 3 Miscellaneous Goggles, Glass (pair) 1 Oil Can, 1/2 litre (1 pint) 1 Oil Stone, double faced 1 Punch, Center 1 Soldering Iron (60 watts, 100 watts) 2 Stamps, 3 mm (1/8") set of letters and numbers - 1 - 22 - 7 @ 2 Machine Tools Machine tools are not essential for the production of 'Triple E Physics' equipments However , they do make the process of production so much quicker and easier , and there is no doubt that cottage industries will find the items listed below a distinct asset* Specifications indicated below are approximate , and only intended as a guideline . 3 phase motors are preferred , being cheaper and more economical to run, but all machines may be bought with either 1 phase or 3 phase motors depending on the supply available . Voltage depends on the local supply , while horse power is a matter of personal preference , but the lower the power the cheaper the machines 1 Bandsaw (1/2 HP) 400 mm (16") Throat 1 Circular Saw (1 HP) 250 mm (10") Blade, Tilting Table Mitre Gauge , Fence „ Guards 1 Drill Press (1/2 HP) 12 mm (1/2") Capacity Chuck, Variable Speed 1 Grinder (1/2 HP) 150 mm (6") Wheels , double ended 1 Metal Lathe (1/2 HP) Bench Type, Screw Cutting Center Lathe, Variable Speed (40 - 1500 rpm) , Reversing Switch „ Gearbox and Automatic Apron , Centers placed at height of 100 mms (4") with 600 mms (24") between Centers : - 3 Turning Toolholders (right hand, left hand, straight) with Bits - 3 Parting Off Toolholders (right hand* left hand, straight) .with Bits - 1 Three Jaw, Self Centering Chuck and Backplate, 120 mm (5") - 1 Four Jaw, Independent Chuck and Backplate, 150 mm (6") - 1 Knurling Toolholder with Steel Knurls - 1 Double Ended One Piece Boring Bar - 1 Face Plate , 200 mm (8") diameter - 3 Lathe Dogs, 6, 12, 25 mm (1/2", 3/4", 1") - 1 Drill Chuck, 12 mm (1/2") capacity, with No„ 2 M 9 T e - 1 Rotating Center with No, 2 M 9 T 9 - 1 Draw in Collet Attachment - 1 Set of Collets, 12 mms (1/2") maximum size - 1 Quick Change Tool Post - 4 Quick Change Tool Holders -23- Further items are not essential . However f for those wishing to make their workshop facilities complete the following items may be added. 1 Buffing Machine (1/2 HP) with R 9 H 6 and L 8 H„ Extension Spindles , Polishing Mop and Wire Brush 1 Oxy-acetylene Set (Very limited usage) with Oxygen and Acetylene Regulators % Welding Torch (with Tips)* Cutting Torch (with Nozzles and Cutting Guide) f Hosing and Goggles 1 Planer (1 HP) 15 cm (6") Blade, Tilting Table 1 Woodlathe (3/4 HP) Centers located at height of 15 cms (6") 9 admitting 75 cms (30") between Centers, Complete withs - 2 Handrests, 200 & 400 mms (8" & 16") - 2 Face Plates t inner 200 mm (8") and outer 400 mm (16") - 3 Centers (1 cone, 1 fork, 1 cup) - 1 Set of Hand Turning Tools with long blades 150 to 200 mms (6" to 8") - 24 - 7„3 Raw Materials This list is not a complete itemization of all the raw materials used in a production workshop,, It is simply an indication of the type of materials in constant use which would tend to form the basic stock of any production workshop , and which are worth ordering in limited quantities for any newly established workshop 8 Adhesives All Purpose Cement (Elmers , Duco) Epoxy Resin & Hardener (Araldite) Rubber Cement (Rugy) Wood Glue (Weldwood) Cellophane Tape Plastic Tape Electrical Materials Bulbs with Holders (1 9 2, 2*5, 6 8 2 volts) Dry Cells (l a 5 volts) Electrical Wire (Cotton or Plastic covered) Fuse Wire (Assorted) Magnet Wire (#20, 22, 24, 26, 28, 30, 32, 34) Nichrome Wire (Assorted) Parallel Electrical Cording Plugs Glass and Plastic Acrylic (Plastic) Sheets , 2 cm and 2*5 cms thick Plates (Glass), 56 x 56 x e 3 cms (22" x 22" x 1/8") Tubes (Glass), 3, 6 mms (1/8", 1/4") internal diameter) Hardware Bolts and Nuts - Brass 3 mms (1/8") diameter, 12, 24, 48 mms (1/2", 1", 2") lengths ; 5 mms (3/16") diameter, 24, 36 mms (1", 1 1/2") lengths' - Steel 5 mms (3/16") diameter, 12, 24, 48, 96 mms (1/2", 1", 2", 3") lengths - Nails, 12, 24, 36, 48, 60, 72 mms (1/2", 1", 1 1/2", 2", 2 1/2", 3") lengths - Sandpaper (00-2) and Carborundum Paper (120 - 500) - Screws - Cup Screws - Wood Screws 12, 18, 24, 36 mms (1/2", 3/4", 1" 1 1/2") lengths - Thumb Tacks - Washers (Brass), 6, 9 mms (1/4", 3/16") diameter - Wingnuts (Steel), 9 mms (3/16") - Wire (Steel), #20, 26, 30 ! < I i _ 25 - Lumber Boxwood (Packing Case Material) Hardboard, 6 mms (1/4") thick Kiln Dried Wood, 2.5 x 15 cms (1" x 6") cross section 1.2 x 15 cms (1/2" x 6") cross section Plywood, 6, 12 mms (1/4" , 1/2") thickness Metals Bars - Brass , 12 x 3 mms (1/2" x 1/8") cross section ~ Mild Steel, 12 x 3 mms (1/2" x 1/8") 18 x 3 mms (3/4" x 1/8") - Tool Steel, 9 x 9 mms (3/8" x 3/8") 40 x 40 mms (1 3/5" x 1 3/5") - Spring Steel, Packing Case Bands Rods - Aluminum , 50 mms (2") diameter >, - Brass, 2, 3, 9, 12, 18, 36 mms (1/16", 1/8", 3/8", 1/2", 3/4", 1 1/2") diameters ~ Mild Steel, 6, 9 mms (1/4", 3/8") diameters - Stainless Steel, 2 mms (1/16") diameter Sheets - Aluminum, 0*2, 9 4 9 0*8, 1.6, 3.0 mms (1/100", 1/64", 1/32". 1/16", 1/8") thickness - Brass, 0.4, 0.8, 1.6, 3*0 mms (1/64", 1/32", 1/16", 1/8") thickness - Copper, 0.8 mms (1/32") - Iron, 1.6 mms (1/16") - Lead, 0.8 mms (1/32") - Zinc, 0.8 mms (1/32") Tubes - Aluminum, 9, 12 mms (3/8", 1/2") internal diameter .- Brass, 5 mms (3/16") internal diameter Paint Materials Alcohol (Denatured) Paint Thinner , fT~ Enamel (Black) Primer Enamel (White) Putty Lacquer, Clear Shellac Lacquer Thinner Wood Filler Paint Brushes . 26 - Miscellaneous Aluminum Foil Carbon Paper Cartolina Containers (Plastic or Glass) Corks (Rubber or Cork) Grease Machine Oil Metal Polish Modelling Clay (Plasticene) Paper Clips Pensg, Felt (Marking Pens) 1 Rubber Bands Soldering Lead Soldering Paste Straws String (Cordp Cotton„ Nylon) 7 o4 Adhesives The following guidelines for fastening materials together should prove to be useful to those undertaking equipment making for the first time. Metals Material Aluminum to Aluminum Brass to Brass Copper to Copper (Magnet Wire) Steel to Steel Steel to Brass Windings of Magnet Wire (layer to layer) Wood Glass to Wood (Ripple Tank) Metal to Wood Wood to Wood Miscellaneous Any Combinations of Materials e s g 9g Glass t Metal^ Paper^ Wood # etc. Adhesive Rivets 9 Screws Rivets $ Screws $ Solder Solder Rivets f Screws $ Solder , Welding Rivets „ Screws, Solder Varnish Asphalt Based Cement Screws Screws , Wood Glue (Weldwood) Any All-Purpose Cement e.g.,,, Duco Cement^ Elmers Glue t Epoxy Resin & Hardener , Rubber Cement „ etc. lij - 27 - 7.5 A Workshop Plan The following is the plan of the workshop in which the first complete set of 'Triple E Physics' materials was produced* It is not offered as an ideal layout. It was in fact somewhat cramped, but it proved to be more than adequate for the development of all the prototype equipment 9 and was considered large enough to produce a complete set of class materials. OC_aJ(sL fVVeu it- 1 9 Experiment Table 2. Office Table 3. Storage Shelves 4 . Storage Racks 5. Woodwork Benches 6, Metalwork Benches 16. 7* Circular Saw and Planer Combined 23 8, Band Saw A 9. Woordwork Lathe 10. Metalwork Lathe Iff! 11, Metal Polisher (Horizontal) 12, Grinder 13, Polisher (Vertical) 14, Bench Drill Press "z^".. 15, Oxy-Acetylene Equipment 16, Hand Tool Cupboard 220 volt Electrical Outlet Gas Outlet Sink with Running Water Electrical requirements depend on machines ordered , and may be single phase or 3 phase 9 and possibly both. Similar considerations affect the voltage provided. » 28 - 8o _JiABQBATORY ..FACILITIES In designing a laboratory to meet local requirements several variables must be taken into consideration These include the prevailing climatic conditions 9 local availability (or otherwise) of mains water electricity and gas j the nature of experiments to be performed $ the type of apparatus to be utilized g and the teaching techniques to be employed in the laboratory . From country to country conditions of temperature , humidity , dust t prevailing winds , precipitation^ and lighting vary considerably, and each individual country is the best judge of its own specific problems • In tropical countries 9 for example $ the problem of humidity and temperature necessitates particular attention being given to cross ventilation to insure personal comfort for the student , This means that the creation of blackout facilities for optical experiments and ripple tank work gives rise to problems , if windows must be covered,, One simple solution is to design apparatus to function efficiently under daylight conditions by using high powered light sources . For this the availability of mains electricity is a major asset a It is important that consideration should be given to how laboratory facilities are to be used in practice . There is little point designing a laboratory for individual student experimentation if the cost of apparatus limits activities to class demonstrations • Equally well it would be wrong to procure small scale apparatus (intended for individual student use) if it was to be used for class demonstrations,, It follows that there is no single blue-print for a laboratory f and the design of the Economy laboratory presented is simply one of many possibilities. This laboratory is primarily designed for a secondary school in a tropical country , and tackles the typical climatic problems that must be considered® It is also designed for small student group experimentation • 8»1 The Economy Laboratory Layout The size of the Economy Laboratory depends upon the maximum number of students likely to occupy the laboratory at any given time g space being allocated at the rate of approximately 3 square meters (33 sq ft„) per student % an additional area of 10 sq„ meters being provided for the workshop - 29 - preparation room* It is important to stress that in following an inquiring approach the teacher is normally very much in demand as a consultant , and ? if the system is to work efficiently , class numbers must be kept to a minimum,, It is realized that large classes are not uncommon in Developing Countries , but it is strongly recommended that every attempt should be made to limit laboratory classes to approximately 32 students , looking on numbers in excess of this as a temporary state of affairs,, Overleaf is a typical laboratory layout for 32 students (working in pairs) with 4 students at each table,, (It would not be difficult to seat 48 students in the same laboratory by placing 6 at each table , particularly if the experiment tables were lengthened by 30 cms,, and the laboratory size increased accordingly . However t a great deal would be lost by students working in larger groups,, 3 to a group, and the temptation should be resisted) The layout indicated is not the only possibility by any means „ but what- ever arrangement is chosen , it should be flexible,, and should permit the teacher to circulate freely amongst the students at work,, and should give ready access to apparatus cupboards . Location of windows should insure good lighting and cross ventilation (particularly in hot countries), and cupboards should be located accordingly . Above all, laboratory arrangements should be flexible , permitting regrouping of furniture according to the specific needs of the class • Four such re-arrangements are illustrated in the plans presented, indicating how the laboratory might be arranged for normal experiments, for ripple tank work and for discussion groups,, Such flexi- bility cannot be achieved without paying careful attention to the design of laboratory furniture , and this is discussed in detail following the j— presentation of the floor plans . - 30 - %\5 _^>j LEGEND A WINDOWS B TABLE TOP WALL BENCH C CUPBOARD D DEMONSTRATION TABLE E EXPERIMENT TABLE W WORKBENCH SH OPEN SHELVES H ELECTRICAL OUTLET O STOOL [j["[ SINK WITH TAP SCALE I CM » I METER LiJ^J^J^J^^t i$;w O I 134. m 1 j ECONOMY LABORATORY Layout for normal experiments - 31 - m LEGEND A WINDOWS B TABLE TOP WALL BENCH C CUPBOARD D DEMONSTRATION TABLE E .EXPERIMENT TABLE W WORKBENCH SH OPEN SHELVES £3 ELECTRICAL OUTLET O STOOL SINK WITH TAP W] RIPPLE TANK SCALE 1 CM = 1 METER o i X 3 *■ S A u ECONOMY LABORATORY Layout for Ripple Tank Work . 32 - LEGEND A WINDOWS B TABLE TOP WALL BENCH C CUPBOARD D DEMONSTRATION TABLE E EXPERIMENT TABLE W WORKBENCH SH OPEN SHELVES \W\ RIPPLE TANK ggj ELECTRICAL OUTLET O STOOL SINK WITH TAP SCALE 1 CM - 1 METER O I X J 4 S' metERs W SH At«fAftA1t»tJ RooM I- ® A HI fl g i S I LP m & i •S J> ,ffl e e e B If at E E E § s s 11 1 fl e ! 1 n U ECONOMY LABORATORY Alternative Layout for Ripple Tank Work U - 33 - LEGEND A WINDOWS B TABLE TOP WALL BENCH C CUPBOARD D DEMONSTRATION TABLE E EXPERIMENT TABLE W WORK BENCH SH OPEN SHELVES (33 ELECTRICAL OUTLETS O STOOL r~j|j SINK WITH TAP SCALE 1 CM - 1 METER L i I I I L-IaJLiJ ECONOMY LABORATORY Layout for Demonstrations and Discussion Groups - 34 - Student Tables Although the student experiment table should be of sturdy design (with a good horizontal surf ace) , it should not be fixed to the floor 8 whether deliberately ? or accidentally (by water or electrical conduits) , for it is intended as a mobile unit 9 A table top 180 x 90 cms is suitable for A students (working in pairs on either side of the table) , particularly if an open shelf is provided for books 9 leaving the top surface completely free for apparatus. The height of the table is a matter of personal choice , and may vary from 75 to 90 cms* depending on the height of the student , and the teacher f s philosophy . There is a tendency nowadays to prefer a high table , since a great deal of experimenting is done in a standing position with resulting discomfort if this necessitates a stooping positions n lJ n r SSomS I §qfkct Qlt€<K ISo^Qcwi Qp£*A Sv*£LV m i' \ tOom TnS«V m Student Experiment Table with Stool . J LJ Table Height and Posture „ 35 - Table Top Wall Benches The table top wall benches provide students with water and electricity outlets. The latter are used primarily as a means of illuminating ripple tanks and optical light sources . High wattage bulbs may be used if mains electricity is connected to the electrical outlets , thus permitting experiments to be conducted without blacking out the laboratory . Should mains electricity not be available^ the same outlets may be supplied from .12 volt batteries 9 placed on the open shelf beneath the bench . Unfortunately , lower wattage bulbs must then be used f and at least partial darkening of the laboratory becomes necessary . This inevitably gives rise to additional problems in tropical countries. As an interim measure batteries may be extremely useful 9 but in the long term they are inconvenient and uneconomic 9 and should not be considered as a permanent solution to the electrical supply problem. .p-i ToVAeTcp (Sink(S) hidden by front panel. Battery (B) wired to outlets if no mains electricity is available) . f.r-i - 36 - The table top wall benches may also be used for project work and standing displays! particularly if the uninterrupted top surface area is increased by the provision of wooden sink covers • Should a mains water supply not be available this need not act as a deterrent to experimental work* A water can placed above (or on) the bench can provide water 9 while a bucket beneath the sink can take it away* This p of course , is not as convenient as having tap water laid on p and should be considered only as an interim measure . Demonstration Table fttr«c\*« J to WftU s^w Co^i* w»;^ %'^cV^.V The teacher's demonstration table could be almost the same as the student experiment table , with the addition of a sink and electrical outlet (preferably 110 or 220 volts AC t but as already mentioned 12 volts DC could be used instead) , but it is invaluable to include a few drawers and cupboards for extra storage space,, u SVultA^S Demonstration Table - 37 - E"Vfc.>|cO%GV\ r<xc\w "VctoA SutP^u^ Rrtc, 3*0*^0 OmS Demonstration Table An apparatus trolley stored alongside the table usefully extends the demonstration surface , a small clip holding the trolley firmly to the table* Many teachers prefer the table to be elevated on a platform about 15 cms high* This is a matter of personal choice % but 9 if it is done, the trolley should be removed and the table extended to measure 250 x 90 cms . Blackboard The blackboard should be located on the wall behind the demonstration table 9 reaching from table top height (85 cms) to the full reach of the teacher . The higher the blackboard the better the visibility for the student 9 giving some justification to those who choose to place the demonstration table on a platform* a) Without Platform $* 4 £ T,,V,\< JT:V*:X=I:«:» 1*0 b) With Platform (370 x 180 cm) Location of Blackboard - 38 - Cupboards Many schools prefer to locate storage facilities in a separate store room for security t but if apparatus is to be used to the optimum extent it should be placed as accessible as possible,, preferably in the laboratory itself . It is therefore well worthwhile securing the whole laboratory % rather than a single store room* The tendency to make cupboard doors of wood or metal , for security reasons % should be avoided , for apparatus is more readily located when the doors are of glass t and is therefore more likely to be used* Shelves could of course be left open g but doors do preserve apparatus by excluding grime and dirt, U L : j I*- %o +1 /D0 _ _ _ I ts- -"I T I I - --I jo i-J n S Cupboards They are also essential if humidity is to be controlled (as in tropical countries) by the location of a 40 watt bulb in one or more cupboards. In the long run the most important factor in preserving apparatus will be regular cleaning by the laboratory assistants Cupboard shelves should n : "1 _ 39 - be adjustable to cope with varying sizes of apparatus , and to give flexibility of arrangement t while glass doors should be hinged so that shelves , or apparatus stores on trays (in class kits) $ can be removed from the cupboard without difficulty • ftA^WlV SWW ftpoc*^ s ^5 Adjustable Shelves Reference Library It is well worthwhile setting aside two shelves , for books and periodicals , to act as a class reference library • This should be a corner for stimulating reading , not for boring college textbooks . Readers written specifically for such programs as the "PSSC" 9 "Nuffield O-Level Physics" and "Harvard Physics" , and science magazines , of the caliber of "Scientific American", provide ideal reference material 8 ftuioJlt'CAlS f^woV Reference Library - 40 - However , one should not overlook references such as biographies 9 which follow the trials and tribulations of scientists % or narratives which relate social progress to scientific advancements f both of which have considerable student appeal. Examples of such materials ares a) "The Century of the Surgeon" by Jurgen Thorwald "The Century of the Detective" by Jurgen Thorwald, two "Reader's Digest" condensed books which not only capture the excitement and allure of science % but also depict its impact on society • b) "Reviving Minds by Brain Surgery" by Dr 8 Hakim An article from "Life Magazine" (May 1967) describing the discovery of a surgical treatment for hydrocephalus depending on Pascual's Law of Balancing Pressures . c) "Madame Curie „ First Lady of Science" "Dr 9 Burkitt Tracks a Cancer Clue" two articles from a "Reader's Digest" magazine (October 1968) , the first a very human biography 9 and the second an excellent insight into the processes from which theories emerge. Floor Insulation In finalizing the laboratory f note should be made of the fact that students may be using mains electricity (110 or 220 volts) , and appropriate safety measures should be taken* It is a wise precaution to cover laboratory floors with an insulating materials Few schools will be able to afford vinyl floor covering , but many will be able to make use of local wood* Bare concrete „ particularly when wet f can lead to dangerous accidents . Workshop Teachers with an aptitude for "tinkering" , or provided with a laboratory assistant (technician) 9 will wish to make full use of the workshop areas in the preparation room 9 The type of handtools and raw materials which might be found useful in such a workshop are listed under "Workshop Facilities" (Chapter 7), _ 41 - Science Wing — —■ t —a t i , • »— it— *» ■ In developing a physics laboratory it is worth considering science requirements as a whole „ Location of laboratories side by side not only insures optimum use of mutual facilities (such as the workshop) $ but also encourages cooperation between the individual scientific disciplines * A possible layout for a science wing is illustrated below* Large schools may require two laboratories for each scientific discipline , in which case C item sir*/ 1 CuCittf .*/\ LfttoPATo&'-f __ BJii0 .'^ PlWS Co(?g»feo^ Science Wing preparation and workshop facilities may be shared between two physics laboratories 9 with a mutual store room for more expensive items of equipment which the school cannot afford to duplicate . CoRfUDo©, Physics Wing - 42 - 8»2 The Normal Laboratory Most teachers will have noted that the Economy Laboratory omits several facilities normally found in more normal laboratories $ and it is worth considering these separately s not only to convince the teacher of the adequacy of the Economy Laboratory $ but also to indicate possible directions for future developments Dark Room Facilities and Ventilation The most important omission is that of blackout facilities 9 or a dark room* Many optical experiments can be performed without difficulty in a normal § well lit laboratory,, and a dark room is considered as a luxury item for the future 9 when photographic work becomes a normal part of the course 9 and more sensitive optical apparatus makes black out B D SH W JL s IE GEND (*• ■ %ts. -M«- 3.*S T 110 TABLE TOP WALL BEECH DEMONSTRATION TABLE OPEN SHELVES WORK BENCH EffiGTRICAL OUTLET (110 or 220 Vo! SINK WITH TAP SCALE 1 CM=1M W PfeEMftftTieii. 8 «° «- Wa&*sa©p L » I 4_j J. ±_i_J Meters tf*& ,fc^ SM bmK Roosi © i 3> 3 LAfeoRAToft"/ 4c ■toj Licsht Location of Dark Room conditions essential . The space next to the preparation room would be ideal for such a future development „ Schools in tropical countries would need to avoid eliminating ventilation in the dark room g despite the need to black out existing windows 9 and could achieve this to some extent by replacing the conventional door by a light trap 9 and by installing sloping ventilation shafts in the walls . The resultant blackout conditions would be adequate for most purposes , so long as the walls were painted with black matt paint „ - 43 - i. Ventilation Shafts •Blacking out the laboratory itself is another problem the teacher would have to face if projectors were to be used in the classroonu Such apparatus is considered beyond the means of the average school 9 but is worth considering for the future . Wooden louvres could exclude light reasonably well, but tend to continue to exclude too much light from the laboratory when actually open* Roller blinds would therefore be considered more suitable . Once again tropical countries would have to make provision for adequate ventilation by means of slanting ventilation shafts in the walls e The apparatus trolley , already referred to, could be used as a projector standi particularly if the height of the upper surface could be adjusted , while a permanent screen located above the demonstration table would enable projection work to go ahead without relocation of students, encouraging greater use of such facilities* - 44 - Blackout Material Wooden Frame tai m m QJTLQ I UleoJUvt f r»w»* Co*i Roller Blind rofw Projector /Apparatus Trolley - 45 - |00 om C -i-A TAW. &\*cV\koutA Projection Screen - 46 - Mains Supplies The Economy Laboratory would make use of simple alcohol or kerosene burners for most heating purposes • However 9 looking to the future most teachers would prefer to have gas available from either gas tanks or the mains, not only because of the convenience, but also because of the better flame that can be provided , Similarly the Economy Laboratory would make considerable use of dry cells for electrical experiments^ but looking to the future it would be very useful to have a 10 volt DC supply in the laboratory,, Such facilities might be installed at the teacher's demonstra- tion table and in the workshop „ where they would be extensively used„ while extension to the wall benches and experiment tables would prove to be a most valuable addition , Such facilities are included in the Normal Laboratory Plan overleaf • The layout presented could be identical to the Economy Laboratory already discussed,, but interesting insights may be gained by presenting an alternative arrangements The new layout would require somewhat greater space , but would have the advantage of students never sitting with their backs towards the demonstration table,, so that short discussions and film projection would be possible without changing the seating arrangement* Students would also be somewhat more accesible to the teacher , and apparatus to the class . The major problem of such an arrangement would be in making gas and electricity supplies available to students without fixing the tables in permanent positions . This could be achieved by the use of raised floor outlets (as well as table outlets) with appropriate connections that could be disconnected,, A better system would probably be that of using independent columns to carry the mains supplies to the tables . On moving the table the supply column'would be lef t __, protruding „ but would not be a deterrent to flexible arrangement of furniture* „ 47 - V 4 6WcW\ 0JWV- L 8 oawv Root O^W r r r Floor Outlets Column Outlets 48 - LEGEND A WINDOWS B TABLE TOP WALL BENCH C CUPBOARD D DEMONSTRATION TABLE E EXPERIMENT TABLE SH OPEN SHELVES W WORK BENCH Ija ELECTRICAL OUTLET (110 or 220 volts AC) P ELECTRICAL OUTLET (10 volts DC) h GAS OUTLET rs^-J SINK WITH TAP Q5g FLOOR OR COLUMN OUTLETS (Equivalent to Sa6 ) O STOOL ' SCALE 1 CM = 1 M o » t a w s Meters N n i. 'j Normal Laboratory Layout for Experiments - 49 - LEGEND A WINDOWS B TABLE TOP WALL BENCH C CUPBOARD D DEMONSTRATION TABLE E EXPERIMENTAL TABLE SH OPEN SHELVES W WORK BENCH JS ELECTRICAL OUTLET (110 or 220 volts AC) P ELECTRICAL OUTLET (10 volts DC) v S GAS OUTLET nfj SINK WITH TAP CFT\ FLOOR OR COLUMN OUTLETS (for 2 groups of students 9 equivalent to KO<t> ) O STOOL RIPPLE TANK SCALE 1 CM - 1 M RT L A™i___L_i_-L i JL-L-J L. &'. w SH Wo&KSWoP s E 1 % 1 I Li CAT ■TMP ^ arm ft Meters Normal Laboratory Layout for Ripple Tank Work - 50 - f : ^ A B C D E SH W □ in O LEGEND WINDOWS TABLE TOP WALL BENCH CUPBOARD DEMONSTRATION TABLE EXPERIMENT TABLE OPEN SHELVES WORK BENCH ELECTRICAL OUTLET (110 or 220 volts AC) ELECTRICAL OUTLET (10 volts DC) GAS OUTLET SINK WITH TAP FLOOR OR COLUMN OUTLETS (Equivalent to C3pd) STOOL ■ SCALE 1 CM* 1M J_LJt j > | Meters L jT n Normal Laboratory Layout for Discussions - 51 - With such a layout the table top wall benches at the sides of the laboratory could be redesigned to include useful cupboard space below while appropriate sections could be replaced by glass cupboards if additional storage was required . \S W f_ 0*>gM SNEl.? Table Top Wall Benches with Cupboard Space In finally deciding what facilities should be developed the teacher should question the necessity g in each case^ of the inclusion in the laboratory of the additional items generally found in the Normal Laboratory .